Lid for egg carton



March 5 I A. P. ERVYHART ETAL 3,

LID FOR EGG CARTON Filed May 2-3. 1967 INVENTORS. find/6w Paul (Fr/701')John 4. Young Jr'.

ATTOR s.

United States Patent Ofifice 3,372,856 Patented Mar. 12, 1968 3,372,856LID FOR EGG CARTON Andrew Paul Erhart, Ponca City, 01:12., and John A.

Young, Jr., Shawnee Mission, Kans., assignors to Burr! & FletcherCompany, Kansas City, Mo., a corporation of Missouri Continuation-impartof application Scr. No. 492,442,

Oct. 4, 1965. This application May 23, 1967, Ser.

4 Claims. (Cl. 229-51) ABSTRACT OF THE DISCLOSURE The rim of a generallyrectangular carton bottom provides a seat for a sheet of cardboardmaterial having spaced, parallel fold lines therein overlying the rimand defining a marginal flap between each fold line and the adjacentedge of the sheet. The grain of the cardboard material extends at aright angle to the fold lines. Upon application of the sheet to thecarton bottom to form a lid therefor, the flaps are folded downwardlyinto engagement with the sidewalls of the carton bottom and are attachedthereto. A tear strip in the central stretch of the sheet between theflaps is defined by a pair of spaced series of cuts, each of the cutsbeing angularly disposed with respect to the grain and the fold lines.

This application is a continuation-in-part of application Ser. No.492,442, filed Oct. 4, 1965, now abandoned.

This invention relates to a lid for egg cartons and, more particularly,to a lid which is initially separate from the carton bottom and whichconstitutes a single sheet of material which is placed in overlyingrelationship to the carton bottom whereby to close the same, the lidbeing provided with a tear strip which may be utilized to gain access tothe interior of the egg carton or the like.

The most important object of this invention is to provide a lid for eggcartons or the like which is fabricated from a, single sheet ofmaterial, the sheet of material being provided with a pair ofspaced-apart, substantially parallel lines of weakness whereby to definea pair of opposed, marginal flaps, there being a central stretch ofmaterial between said lines of weakness, a pair of spaced apart seriesof cuts defining a tear strip throughout the length of said centralstretch, the various lines of weakness, series of cuts and cut linesdefining saidseries being arranged in such a manner with respect to thesheet of material and the grain thereof, whereby maximum strength isretained by the lid so that the lid, in both its blank and finishedform, may be handled without buckling or giving as the blank is handledand placed upon the carton bottom.

Yet another important object of this invention is to provide a lid foregg cartons or the like which is formed from a substantially rectangularsheet of material, the sheet having spaced-apart lines of weaknessformed therein, there being a central stretch of material between saidlines of weakness, the central stretch of material having a series ofcuts disposed therein, the series of cuts being spaced apart asuilicient distance to define a tear strip of the desired widththerebetween, the cuts constituting each series being angularly disposedwith respect to the grain of the cardboard forming the lid and the linesof weakness, the angular disposition of the tear'strip de fining cutsinsuring that the said central stretch will not bend or otherwise givewhen the lid is bent along the above-mentioned lines of weakness as itis being placed upon the carton.

Yet another important object of this invention is to provide a lid forcartons wherein the grain of the card board forming the lid istransverse to the longitudinal axis of the lid, all to the end that thelid, and most particularly the central section thereof, will not bowoutwardly as the marginal edges of the lid are folded downwardly intoengagement with the sidewalls of the carton.

Other objects of the invention will become apparent from the followingspecification and accompanying drawin g, wherein:

FIGURE 1 is a perspective view of an egg carton with the lid in placethereupon;

FIG. 2 is a top plan view on a reduced scale, a portion of the lid beingbroken away;

FIG. 3 is a top plan view of the blank which forms the lid; and

FIG. 4 is a sectional view taken along line 44 of FIG. 2.

The lid 10, while it may be used in connection with various types ofcarton bottoms, is illustrated in the accompanying drawing asconstituting a cover, lid, closure or the like for a molded pulp eggcarton 12, said carton having a pair of opposed sidewalls 14, a pair ofopposed end walls 16, said walls and intermediate portions thereofcooperating to define a plurality of pockets or cells 18 for receivingthe desired number of eggs in the carton bottom. A rim 20 is defined bythe normally uppermost edges of sidewalls 14 and end walls 16, said rimserving as a seat for the lid 10 when said lid 10 is disposed inoverlying relationship to the carton bottom 12, the lid 10 serving toclose the upper end of each of said cells or pockets 18 when positionedthereupon.

Lid 10 is formed from a substantially rectangular sheet of cardboard 22,shown in its blank form in FIG. 3 of the drawing, which sheet ofmaterial 22 is substantially rectangular in plan configuration wherebyto present a pair of end edges 24 and a pair of side edges 26, the blank22 having a normally uppermost surface 28 and a lower surface 30.

Blank 22, as indicated, is fabricated from cardboard or the like andinasmuch as said board has a graining characteristic therein, it isdesirable to have the grain of the board from which blank 22 is formed,extending transversely of the blank, that is in perpendicularrelationship to the opposed side edges 26. By forming blank 22 in such amanner, additional strength is imparted thereto, which strength isuseful in handling the blank prior to its installation in overlyingrelationship to the carton bottom 12 and is also useful in addingstrength to the lid 10 when it is positioned upon bottom 12.

Blank 22 has a pair of lines of weakness 32 and 34 formed therein, saidlines 32 and 34 each being spaced inwardly from a corresponding sideedge 26 whereby to present between each of said lines 32 and 34 and itscorresponding side edge 26, a marginal flap 36. Said lines of Weaknessare in the nature of spaced-apart, longitudinally extending, beingformed by cutting into the cardboard forming the blank at closely spacedintervals whereby the marginal flaps 36 may be bent with respect to theremainder of blank 22 when lid 10 is positioned upon carton bottomaligned score lines, the score lines 12. It will be noted that the linesof weakness 32 and 34 extend longitudinally of blank 22 and inasmuch asthe graining of the cardboard which forms blank 22 is positionedtransversely thereof, the graining and the lines of weakness are inperpendicular relationship.

Defined between the lines of weakness 32 and 34 is a central stretch ofmaterial 38, said central stretch of material constituting the remainingportion of normally uppermost surface 28 of blank 22, it beingcontemplated that stretch 38 will be in overlying relationship to thepockets of the carton bottom 12.

A tear strip 40 is defined throughout the length of central stretch 38by a pair of spaced-apart series of cuts 42 and 44, said series of cutseach consisting of a plurality of individual cut lines such as 46, saidcut lines being angularly disposed with respect to the lines of weakness32 and 34 and also the side edges 26 of blank 22.

It will be appreciated that the tear strip 40 may be of any desiredwidth, depending upon the distance by which the series of cuts 42 and 44are spaced apart within the transverse limits of the central stretch 38it being noted that in the embodiment chosen for illustration, the tearstrip 40 is relatively narrow and the series of cuts 44 is directlyadjacent one of the lines of weakness 34, the other series of cuts 42being positioned only slightly inwardly from line of weakness 34 wherebyto define said narrow tear strip.

It will be appreciated however, that the tear strip could constitute theentire central stretch 38 and that if this were desired, the normallyinnermost series of cuts such as 42 in the embodiment chosen forpurposes of illustration, would be moved into adjacent relationship withline of weakness 32 at the opposite longitudinal edge of the centralstretch 38. Thus. by properly arranging the spacing between the seriesof cuts 42 and 44, a tear strip of any desired width may be obtained.

Positioned at the end of tear strip 40 is a tab 48 which is utilized toremove the tear strip by pulling upwardly, thereby causing s-aid seriesof cuts to cooperate and tear along the outer edges thereof, thuseliminating a portion of the central stretch 38 after the tear strip hasbeen utilized. It will be noted that in the embodiment chosen forpurposes of illustration, the tear strip 40 may be removed and when thishas been accomplished, the remaining portion of the central stretch 38of lid may be hinged about line of weakness 32 to provide a swingingcover for the carton bottom 12.

In use, carton bottom 12 is formed independently and blank 22 islikewise formed independently, bottom 12 being made of a pulp materialand blank 22 being of a cardboard material. Lid 10 is then placed inoverlying relationship to carton bottom 12, the lower face 30- of thelid resting upon rim of carton bottom 12. The marginal flaps 36 are thenfolded downwardly into engagement with the corresponding sidewalls 14 ofthe carton bottom, it being contemplated that the lower surface of themarginal flaps 36 will be provided with an adhesive whereby to securesaid flaps, and thereby said lid 10, to the carton bottom 12. Thepackage is then complete and ready for shipment and storage.

When it is desired to utilize the carton, the tear strip is merelyremoved and access is gained to the interior of the egg carton orsimilar container which is provided with a lid such as hereinabovedescribed. The specific graining of the cardboard and the relativeposition of the lines of weakness and series of cuts as hereinabovepointed out, and to be discussed further hereinbelow, are important sothat maximum strength may be obtained in the lid while yet providing thesame with a tear strip for easy access to the interior of the carton.Furthermore, a carton made as described herein is cheaper than a cartonwhich is made completely of pulp and is .also cheaper than a cartonwhich is fabricated entirely from cardboard.

It has been found that the most effective combination of lid rigidityand tearability of the tear strip 40 is pro.- vided by disposing eachcut of the series of cuts 42 and 44 at an angle of approximately 45 withrespect to the direction of tear of strip 40. This also positions thecuts at an angle of approximately 45 with respect to the grain of thecardboard material of blank 22. In general, satisfactory results areobtained as long as the cuts are disposed at an angle from 30 to 60 withrespect to the direction of tear. For adequate tearability utilizingcuts disposed at the 45 angular relationship, the spacing betweenadjacent pairs of cuts 32 or 34 should be approximately 4 to inch, aspacing of inch being preferred.

It is also important that the solid or uncut portion of tear strip 40between the two series of cuts 42 and 44 be at least /2 inch in width toimpart sufficient rigidity to blank 22 as the same is applied andsecured to carton bottom 12. The preferred material for blank 22 is0.022 patent coated newsback boxboard, although cardboard stock having athickness of approximately 0.020 to 0.025 inch is satisfactory from thestandpoints of both the necessary rigidity of the material and therequired tearability thereof along the series of cuts 42 and 44.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. Carton structure comprising:

a generally rectangular carton bottom having upstanding walls providedwith normally uppermost edges defining a rim,

a substantially rectangular sheet of cardboard material having a pair ofside edges, a pair of end edges, and a pair of spaced, substantiallyparallel lines of weakness therein extending from one end edge to theother end edge and disposed adjacent respective side edges in inwardlyspaced relationship thereto, to define a marginal flap between each ofsaid lines and its adjacent side edge and a central stretch of saidmaterial between said flaps,

the grain of said material extending substantially perpendicularly tosaid lines,

the spacing between said lines being substantially equal to the distanceacross said rim transversely of said carton bottom,

said rim presenting a seat for said sheet upon application of the sheetto the carton bottom and when said flaps are folded downwardly alongsaid lines into engagement with corresponding walls of said cartonbottom,

said flaps being attached to respective walls, so the sheet forms a lidwith said central stretch overlying said carton bottom,

said central stretch including a tear strip extending the length of thestretch and defined by a pair of spaced series of cuts therein, eachseries being disposed in substantial parallelism to and adjacent one ofsaid weakened lines,

the cuts constituting each series being entirely angularly disposed withrespect to said grain and said lines.

2. The invention of claim 1,

said cuts extending at an angle of from 30 to 60 with respect to thedirection of tear of said strip,

the width of the strip between the inner terminations of the cuts of oneseries and the inner terminations of the cuts of the other series beingat least A2 inch.

3. The invention of claim 1,

said cuts extending at an angle of approximately 45 with respect to thedirection of tear of said strip,

adjacent pairs of cuts of each series being space apart approximately 4inch to 7 inch.

4. The invention of claim 3,

the width of the strip between the inner terminations of the cuts of oneseries and the inner terminations 6 of the cuts of the other seriesbeing at least /2 inch, 3,162,352 12/ 1964 Swain 229-51 said sheethaving a thickness of approximately 0.020 3,195,800 7/1965 Cote 229-51inch to 0.025 inch. 3,237,842 3/ 1966 Esse Q2951 References Cited 5FOREIGN pAjrpfNTs UNITED STATES PATENTS 1,008,481 10/ 1965 GreatBritain. 2, 1 1 1 1 Cufiey et 22 1 DAVIS T. MOORHEAD, Primary Examiner.

2,975,954 3/1961 Sparks 229-51

